The present invention relates to an encoded symbol reader used to decode encoded symbols such as two dimensional tessellated codes.
Recently, point-of-sale systems have employed encoded symbol readers in order to scan bar-code labels on to increase the speed at which products can be processed through a check-out line of a store. However, bar-code labels store data in only one direction (i.e., the scanning direction) and, therefore can only store a limited amount of data.
To overcome the problem of limited data storage, a new type of symbol which stores data in two directions has been proposed. This new type of symbol (hereinafter referred to as a two-dimensional symbol) uses a tessellated pattern to store the data.
However, in the conventional device, if the size of an image of the encoded symbol that is formed on an image sensor such as a CCD (charge coupled device) varies, the encoded symbol may not be decoded correctly.